490 
double, shows fusion in the frontal region as the neural canals seem 
individual up to the midbrain region. 
Apparently there is but a 
single forebrain vesicle. This embryo was removed from the balsam 

Fig. 2. Double Chick showing fusion 
2 gg 
Fig. 3. Chick showing duplication of pelvic limbs. | 

in the thoracic region. 
and mounted in paraffin 
and sectioned serially. The 
results obtained were not 
altogether satisfactory, but 
drawings have been pre- 
pared and an attempt will 
be made to reconstruct at 
a later date. 
2. This monster (Fig.2) 
represents a later stage of 
development (60—72 
hours). The embryos are 
almost completely separat- 
ed, united only in the 
thoracic region. Each 
shows a complete body 
with no organs in com- 
mon, the hearts being 
especially prominent; al- 
though the heads, necks 
and thoraces are parallel to each other, the bodies diverge at almost 
a right angle to the foregoing parts. The embryo to the right ex- 

